Roll for use in strip and sheet mills



March 21, 1933. C, F KMGHT wuww ROLL FOR USE IN STRIP AND SHEET MILLS Filed Feb. 20 1932 Inventor lamence 7 1 Km 19/25 Patented Mar. 21, 1933 .gyyi

UNITED STATES HAZEL, or YOUNGSTOWN, 01110, AND ONE-FOURTH T0 FRANCIS M. co vrsrocx; DE

WARREN, OHIO CLARENCE F. KNIGHT, OF WARREN, OHIO, ASSIGNOR 0F ONE-FOURTH TO MELVIN ROLL FOR USE IN STRIP AND SHEET MILLS Application filed February 20, 1932. Serial No-. 594,2 97.

This invention relates to broadly to the process of rolling hot and cold strip metal, and more particularly to rolls used for th1s purpose.

In accordance with the present invention, conical or tapered rolls are provided and used in lieu of the cylindrical rolls now in use, and which latter rolls have been found undesirable and ineflicient for the purpose desired.

The cylindrical rolls now in use have a tendency to spring or how in the middle while the bar is being rolled.- By reason of this springing, the finished strip or sheet is several thousandths of an inch heavier 1n the center and is consequently not of uniform gauge throughout the its area. To overcome the heavy center of the sheet or strip 1t is common practice to make a pass through convexed rolls as a final operation. It has been found that the pass through the convex rolls has a tendency to elongate the center area of the sheet causing a buckle.

I propose to eliminate the elongation and buckling in the center of the sheet or strip, and to this end I employ a pair of frustoconical rolls, tapering in opposite directions and having their axes of rotation in the same vertical plane. The result of this construction is a high and low diameter 0posed to each other at the opposite ends of the rolls. hen the bar is passed through these rolls the metal composing the top side of the bar flows to the high diameter of the top roll; while at the same time the metal composing the bottom side of the bar flows to the high diameter of the bottom roll. Thus there is a lateral stretching of the sheet or strip toward the margins of the rolls, that not only overcomes the heavy centers of sheets rolled on cylindrical rolls, but eliminates the buckling and elongation referred to in the use of the convexed rolls. It therefore follows that the rolls of my invention provide a means whereby sheets and strips can be rolled by the method known in common practice as continuous rolling whereby the sheet or strip is progressively reduced by each roll pass to a uniform gauge and without buckling.

V ilvhile-the inventionis particularly adapted to a two high rolling mill, the principle thereof is applicable to mills of more than two high; Furthermore, it is to be understood that backing rolls can be used with the rolls of this invention. Albeit the invention.

is here described andused for rolling steel 7 sheets and strips it is within the. purview of the invention to roll any metal or alloy of any metals. And therolls will operate equally well while rolling hot or cold metal. Referring to the drawing it will be seen that Figure 1 is anelevational view of the roll. Fig. 2 is an end elevational roll thereof. Referring to the drawing, wherein for the purpose of illustration is shown the preferred embodiment of my invention, I provide a pair of rolls5, 6. p These rolls'are adjustably supported one above the other in any suitable housing suggested by the broken lines in Fig. 1 and desig nated generally by the reference character 7. A series of these rolls and their housings may be used so that the bar may be progressively reduced in thickness at each roll pass of the series, which-practice is known as a continuous'rolling mill. I g

The axis of rotation of each roll is in the samevertical plane. Each of the rolls are frusto-conical in shape. The upper r0ll5 tapers with a uniform pitch from one end to the other, and likewise the bottom roll 6 tapers from one end to the other with a uniform pitch. While the pitch of the upper and lower rolls have given satisfactory results when they are identicahjit is conceivable that the pitch might vary slightly without departing from the spirit of this invention. It is also pointed out that the margins of these rolls may be modified to overcome operating faults. For example, overhanging flanges on each roll may be provided to lap each other for reducing end thrust on bearings, without evading the scope of this invention.

The rolls are arranged in the housings with v the high diameter of the stop roll 5 in approximate alignment with the low diameter of the bottom roll 6. The high diameter of the bottom roll 6 is in approximate alignment with the low diameter of the top roll 5. As a result of this arrangement the uniform pitch of the top roll 5 is opposed to the uniform pitch of the bottom roll 6. And the uniform pitch of each roll is coextensive with the axial dimension throughout the entire working surface of each roll.

In operating the present rolls the first set or passhave their peripheries spaced in accordance with the amount of reduction desired. The bar is then peripheries of the rolls, a er which it is conveyed to the next set of rolls for the second reducing pass, and thereafter to the succeeding sets until it is progressively reduced in thickness to a finished sheet or strip at the last pass. The bar is inserted as near as possible to the center of the rolls. From the center line of the rolls, there is set up a lateral stretching of the metal in the bar, toward the high diameters of the rolls, and consequently away from the center. This stretching influence is exerted at each pass and being uniform and progressive, the finished sheet or strip has a uniform gauge throughout its area and entirely free of buckles.

Having thus described my invention, what I claim as new is:

1. A rolling mill comprising plural rotatable rolls, each pair of rolls defining a pass, said rolls having their axes of rotation in the same plane, and each roll tapering in the opposite direction from the other roll with a uniform pitch coextensive with its working surface.

2. A rolling mill adapted for rolling strips and sheets at an angle to the axes of the rolls, comprising plural rotatable rolls, each pair of rolls defining a pass, and each roll tapering in the opposite direction from the other roll with a uniform pitch coextensive with its working surface.

3. A rolling mill comprising dual rotatable oppositely disposed frusto-conical shaped rolls defining a pass, said rolls having their axes disposed in the same vertical plane, and each roll. having the same pitch throughout its axial dimension.

In testimony whereof I afiix my signature.

CLARENCE F. KNIGHT.

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